For some time, known flush toilets configured to be flushed with flush water supplied by jet pump action so as to discharge waste have included, for example, the apparatus set forth in Patent Document 1 (Japanese Patent Unexamined Publication No. 2014-190065). In such apparatus, a portion or flush water supplied from a water supply source is stored, and a tank supplying flush water to the toilet main unit is installed on the top surface of the toilet main unit.
In such conventional flush toilets, a jet pump unit for inducing a jet pump action, and multiple other related parts, are installed within the tank. In order to obtain good jet pump performance in a standalone tank, therefore, it is preferable for the connection between the tank and the toilet main unit to be made outside the tank.
In recent years, however, due to diversification of flush toilet designs and greater water conservation, tanks are disposed in relatively low positions on the rear side of the toilet main unit. As a result, “low silhouette type” tanks are employed, in which the height position of the top edge of the tank is set at a low position, reducing the overall height of the flush toilet. In such low-silhouette type tanks, however, an effort to reduce the span in the front-back direction (depth direction) and width (lateral direction) in the left-right direction reduces dead space, rendering unavoidable designs in which the area around the connecting portion between the tank and the toilet main unit is surrounded.
In designs for tanks and toilet bodies in which the area around the connecting portion between the tank and the toilet main unit is surrounded in this way, it becomes difficult for a worker's hand to directly reach the connecting portion between the tank and the toilet main unit, thus impeding installation requiring direct access. This means that the operation to connect the tank and the toilet main unit in a watertight manner must be achieved by indirect means or method, making it difficult to secure watertightness.
A method is also conceivable in which access to the tank and toilet main unit connecting portion is from the inside of the tank. However, space is occupied inside the tank by many related parts in addition to the jet pump unit. Therefore space inside the tank is also reduced to the extent the tank size is reduced, making it difficult for a worker to gain direct access. This makes it difficult to directly perform the connecting operation needed to assure watertightness close to the connecting portion inside the tank.